Journal of Advances in Environmental Health Research
Volume:11 Issue: 2, Spring 2023

In the last few decades, concern over environmental safety has increased significantly. One of the main causes of environmental degradation is the discharge of untreated pollutants into water bodies. This study examined the efficiency of the photo-Fenton oxidation process to remove chemical oxygen demand (COD) and total organic carbon (TOC) from petroleum wastewater. Experiments were designed using the Box-Behnken method- a model of the response surface method (RSM) by MINITAB software. First, a wooden chamber equipped with UV lamps installed in the center was applied. The effect of effective parameters on the photo-Fenton process, including naphthalene concentration (10-70 μg/L), pH (2-7), H2O2 (50-800 mg/L), Fe (5-80 mg/L), contact time (10-120 minutes) and UV rays was investigated. The highest removal efficiency of the COD (case 89.27) was at achieved at pH = 2, UV = 24, naphthalene concentration 10 μg/L, Fe concentration 36.06 mg/L, hydrogen peroxide content 800 mg/L, and contact time 120 min. Besides, the highest removal efficiency of the process in removing TOC was 71.04% obtained at 2 pH = 24, UV = 24, and a reaction time of 120 min. Based on the results of this research, the photo-Fenton process has a significant efficiency in removing COD and TOC from petroleum effluents containing cyclic aromatic hydrocarbons and can be utilized as an efficient method for the treatment of petroleum wastewaters.

The subject of this study was the application of the electro-coagulation process to a contaminated groundwater identified in the Abala community, which is a suburb of the Ilorin metropolis in Kwara state, Nigeria. The electro-coagulation process was applied to the groundwater samples in a 2.5-L batch reactor containing 1 L of the contaminated water. Each run lasted for 1 hour, and a DC power supply was used with a voltage range of 10 to 20 V at a constant current of 5 amp, or 2amp to 6amp at a constant voltage of 10 V. Also, graphite electrodes were employed in the process. The results revealed that the electro-coagulation process could reduce turbidity, total dissolved solids (TDS), electrical conductivity (EC), biological oxygen demand (BOD), total organic carbon (TOC), chemical oxygen demand (COD), and color by 97.3, 91.2, 91.1, 96, 99.7, 99.7%, 79.9%, and 82.96%, respectively. Through an atomic absorption spectroscopy analytical study, the process also showed removal efficiency of manganese (Mn), iron (Fe), and zinc (Zn) of 82.96%, 70.0%, and 95.30%, respectively. The results of the electro-coagulation process met the drinking water and general industrial wastewater discharge guidelines set by the World Health Organization (WHO), the United States Environmental Protection Agency (USEPA), and the Water Environment Partnership in Asia (WEPA). The observations of this study indicated that electro-coagulation is an efficient and effective treatment method for the contaminated groundwater. Therefore, this study recommends the use of electro-coagulation for treating contaminated groundwater in Nigeria.

One of the most challenging and critical processes in wastewater treatment is sludge treatment. This study aimed to investigate the effects of low frequency ultrasound and high level of energy on inactivation rate of total coliform of sludge and ascertain the optimal operating parameters of the ultrasound waves.

In this research, the density of ultrasound (W/mL) and time (minutes) were investigated. The effect of these parameters on the inactivation of total coliform in sludge was also investigated.

The results revealed that the optimum operating time and ultrasound density were 30 minutes and 2.5 W/mL, respectively. Also, the frequency of 20 kHz of total coliform removal rate in these conditions was 99.44% .

Ultrasound waves as well as micro and nano bubbles could remove total coliform and decontaminate the sludge, thereby incrementing the rate of treatment.

Aniline-based organic nanocomposites have a significant performance as photocatalysts in the advanced oxidation process (AOP). In this study, polyaniline-tin dioxide (PA/SnO2) nanocomposite was prepared using an ultrasonic process. Next, its efficiency as a photocatalyst in the removal of Cefixime antibiotic pollutant from contaminated waters in a tubular photo reactor was investigated. The experiments were designed by the response surface methodology (RSM) via Minitab software, in such a way that the effects of various parameters on the process are investigated. The effect of different parameters such as reaction time, solution pH, flow rate, antibiotic concentration and hydrogen peroxide concentration on the removal efficiency was investigated. According to the results, the following optimal conditions were obtained: time of 120 min, pH of 8.69, hydrogen peroxide concentration of 4.22 mM, flow rate of 1.25 L/min and initial antibiotic concentration of 22.92 mg/L. Under the above-mentioned optimal conditions, the efficiency of Cefixime removal was more than 72.24%. The present study confirms the usability of the PA/SnO2 nanocomposite as a novel and effective photocatalyst for photocatalytic degradation of Cefixime antibiotic in contaminated water under UV light.

Due to lack of attention to the required time of emulating the absorbed doses of drugs from different organs, inappropriate use of antibiotics for disease treatment in animals causes many adverse health effects in consumers. In this study, the antibiotic residues in raw and pasteurized milk were evaluated in Neyshabour city.

Raw and pasteurized milk samples were collected from eight farms and milk collection units and four pasteurized milk production factories in Neyshabour city during the warm and cold seasons. 56 samples of raw milk and 24 samples of pasteurized milk were analyzed using the Copan milk test, Tri-Sensor kit and ELISA detection methods to evaluate presence of the antibiotic residue.

Copan milk test and Tri-Sensor kit did not detect the antibiotic residue. ELISA kit was able to detect the presence of gentamicin and streptomycin in milk. 25% of the samples contained gentamicin, while 10% of the samples contained streptomycin. The amount of antibiotic residue in the warm season was higher than cold season. 58.3% of pasteurized milk samples in the warm season had gentamicin.

Based on our results, extensive and accurate monitoring of antibiotics in raw and pasteurized milk needs to be performed in the city, especially in warm seasons.

Electrocoagulation (EC) is a safe method for removing environmental pollutants without the need for additional chemical materials. This study investigates the performance of EC in removing chemical oxygen demand (COD), total organic carbon (TOC), total suspended solids (TSS), and turbidity from drilling waste generated by oil rigs. An experimental study was performed on a pilot scale in an EC reactor provided from a cylindrical glass cell (height: 30 cm and inner diameter: 5 cm), a pair of aluminum and iron electrodes, a power supply, an aeration system. wastewater Samples were collected from one of the drilling rigs in Khuzestan. The effect of current density, operation time and pH parameters on removal of COD, TOC, TSS and turbidity were determined and the optimal values of the parameters were determined. It was found that system voltage, operation time and pH values on the removal efficiency of pollutants were statistically significant at the 0.01 level. The optimum values of pH, current density and operation time were obtained 7, 20 mA/cm2 and 60 minutes, respectively and the removal efficiencies of COD, TOC, TSS and turbidity under the optimum conditions were 72%, 79%, 67% and 63%, respectively. Also, the consumption of energy was estimated to be 8.4 kWh/m3. The results indicated that the EC process is a cost-effective method in removing pollutants caused by drilling of oil rigs and its efficiency can be improved by applying optimal conditions such as current density and pH.

In the petrochemical industries, accidents are generally catastrophic which endanger human, environment and economic. In the industries, there is a wide range of flammable and toxic substances that affect health and safety of workers. They have also adverse effects on society. Numerical risk and impact assessment as well as design for protective layers against catastrophic events are necessary for designing process units. First, the occupational-process and environmental safety hazards were measured by hazard and operability (HAZOP) and environmental failure mode and effects analysis (EFMEA) techniques. Then, the risk was assessed using the layer and operability analysis (LOPA) method. The results showed that a total of 50 safe and health items and 37 environmental risks were identified by HAZOP and EFMEA methods in Imam Khomeini Petrochemical Aromatic Unit. There were 17, 19 and 14 items with low, medium and high level risk, respectively. This study showed that the LOPA method is more comprehensive than hazard identification methods for the analysis of protective layers. The important actions were blockage of the excess gas to the flare and release the H2S gas. Also, evaluation of the environmental aspects of aromatic unit activities showed that air pollutant production in the power supply unit, waste disposal of reactor tank, waste disposal of condensate tank and reactor fire and explosion were at a high level risk.

Qanat is a valuable source of groundwater, the maintenance of which requires quantitative and qualitative monitoring. Since the qanat water is currently used in some parts of Iran for drinking and agricultural purposes, its quality management is of great importance. This study aimed to evaluate the water quality of the qanat in the eastern areas of Tehran.

Water sampling was performed in eight qanats in the east of Tehran in triplicate (mother well and one of the access shafts and outlet) during the summer of 2020. The measured parameters were pH, total dissolved solids (TDS), electrical conductivity (EC), CO32-, HCO3-, Na2+, Ca2+, Mg2+, K+, Cl-, NO3, SO42-, total hardness (TH) and total alkalinity (TA). The quality was assessed according to the standards introduced by the World Health Organization (WHO) and Food and Agriculture Organization. Groundwater quality index (GWQI) was used to classify the samples.

The lowest (56.05) and the highest (2058.58) GWQI scores corresponded to qanats 5 (Elimon) and 8 (Aminabad) with good and very poor quality, respectively. There was a decrease in the water quality of qanats 8 (Aminabad), 7 (Sulaymaniyah), 6 (Mehdiabad) and 2 (Majidieh), respectively.

The quality of the qanats were in the range of good to very poor. The reasons for difference in water quality could be due to the direction of anthropological pollutants and geological structures. To control the water quality of the qanats in the east of Tehran, the quality monitoring network is recommended to be designed for various pollutants and optimized for long term.